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Biomedical subjects

A J Shorthouse

Publications and source records attributed to A J Shorthouse.

11 recordsLinked to original sources
PubMed1992

Haemorrhoids are associated not with hypertrophy of the internal anal sphincter, but with hypertension of the anal cushions.

A combined manometric and ultrasonographic study of the internal anal sphincter was carried out in 20 patients with haemorrhoids and 20 age-matched normal controls. Mean(s.e.m.) basal anal pressure was significantly higher in patients than in controls, 62(4) versus 45(6) cmH2O (P less than 0.05), although there were no significant differences in mean maximum basal and squeeze pressures. During rectal distension 90 per cent of patients showed no reduction in anal pressure in the outermost anal channel, although the internal sphincter electromyogram was suppressed and the external sphincter electromyogram did not necessarily increase above baseline. The mean(s.e.m.) maximum residual pressure was significantly higher in patients, 70(6) versus 45(6) cmH2O (P less than 0.05). Direct pressure measurement in anal cushions exhibited abnormally high median pressure in patients compared with controls, 35 versus 10 cmH2O (P less than 0.001). Pressures recorded during coughing and straining were also significantly higher in patients than in controls (P less than 0.001). Ultrasonographic study of the anal canal revealed a clear image of the internal sphincter, the thickness of which could easily be measured. The mean(s.e.m.) thickness of the sphincter was not significantly different, 2.3(0.2) versus 2.1(0.1) mm, between patients with haemorrhoids and controls (P = 0.18). The absence of any significant differences in the internal sphincter thickness between normal subjects and patients with haemorrhoids suggests that the high anal pressure in patients with haemorrhoids is of vascular origin.

Adult↗
PubMed1992

Patterns of methylation of the c-myc gene in human colorectal cancer progression.

Over-expression and abnormal intracellular location of the product of the oncogene c-myc in colonic dysplasia and neoplasia may be related to alterations in epigenetic mechanisms controlling the functioning of this gene. We have investigated the methylation patterns of the c-myc oncogene in human colorectal tissue representing various stages of dysplasia and neoplasia, including metastasis to liver, omentum and lymph node. Comparison of normal and neoplastic tissues from the same patient showed a decrease in methylation in a specific CCGG site in the third exon of c-myc through the progression from normal via dysplastic to neoplastic and metastatic tissue. Quantitative analysis revealed that in colonic adenocarcinomas an average of 66.1% and in metastatic deposits 83.1% of the myc gene DNA was hypomethylated at this site, as compared to a value of 9.2% in normal colonic mucosa. Adenomatous polyps showed an average value of 50.5% and hyperplastic polyps, 24.8%. The results suggest that partial hypomethylation of the c-myc gene third exon is associated with cell proliferation, and that deregulation of proliferation may be linked to the high levels of hypomethylation, presumably involving both copies of the gene in some cells, which occur at a relatively early stage in neoplastic progression.

Adenoma↗
PubMed1990

Hypertensive anal cushions as a cause of the high anal canal pressures in patients with haemorrhoids.

Anorectal manometry and electrophysiology studies were conducted in 25 men with non-prolapsing haemorrhoids, ten men with prolapsing haemorrhoids, and 20 age-matched normal men. Mean(s.e.m.) minimum basal pressures were significantly higher in patients with non-prolapsing haemorrhoids than in normals (61(5) versus 43(7) cmH2O; P less than 0.05) or patients with prolapsing haemorrhoids (55(4) cmH2O; P less than 0.05). There were no significant differences in maximum basal pressures and maximum squeeze pressures. During rectal distension, all normal subjects showed relaxation in all anal channels. However, 92 per cent of patients with non-prolapsing haemorrhoids and 40 per cent of patients with prolapsing haemorrhoids showed no relaxation in the outer anal channels, even when relaxation occurred in the inner anal channels; internal sphincter electrical slow waves were suppressed and the integrated electrical activity of the external sphincter had returned to predistension values. Maximum residual anal pressures during balloon distension were significantly higher in patients with non-prolapsing haemorrhoids than normals (75(7) versus 45(7) cmH2O; P less than 0.01), or patients with prolapsing haemorrhoids (53(3) cmH2O; P less than 0.05). When subjects increased intra-abdominal pressure rectal pressure was significantly higher in patients with non-prolapsing haemorrhoids than in normal subjects (157(10) versus 105(15) cmH2O; P less than 0.05), but not in patients with prolapsing haemorrhoids (126(14) cmH2O). Resting anal cushion pressures in patients with non-prolapsing or prolapsing haemorrhoids were much higher than normal capillary or venous pressure and significantly higher than those recorded in normals (median 35, 35 versus 10 cmH2O; P less than 0.0001). Pressures recorded during coughing (60, 60 versus 30 cmH2O) and straining (78, 80 versus 55 cmH2O) were also significantly higher (P less than 0.0001) in patients than in normals. Pressures after straining were higher than those recorded before (38 versus 29 cmH2O; P less than 0.05) in 60 per cent of patients but no normal subjects and took 18-36 s to return to baseline. This study suggests that the abnormally high pressures in the anal canal in patients with haemorrhoids may be related to an increased vascular pressure in the anal cushions.

Action Potentials↗
PubMed1989

A common pathophysiology for full thickness rectal prolapse, anterior mucosal prolapse and solitary rectal ulcer.

Anorectal pressures at rest, during conscious contraction of the external sphincter, during serial distension of the rectum and during straining to inflate a balloon were measured in 56 patients (21 patients with full thickness rectal prolapse, 24 patients with anterior mucosal prolapse, 11 patients with solitary rectal ulcer) and in 30 normal subjects. Both basal and squeeze pressures were significantly lower in the three groups of patients compared with matched normal controls (P less than 0.05). During increases in intra-abdominal pressure, anal pressure remained above maximum rectal pressure (P less than 0.05) in normal controls, with the highest anal pressures being recorded in the most caudal anal channels. In contrast, anal pressures tended to be lower than rectal pressures during this manoeuvre in patients with rectal prolapse, anterior mucosal prolapse and solitary rectal ulcer, and the highest pressures were recorded in the channels nearest the rectum. During serial distension of the rectum, 64 per cent of patients with solitary rectal ulcer, 75 per cent with anterior mucosal prolapse and 76 per cent with rectal prolapse, but only 10 per cent of controls, showed repetitive rectal contractions. The highest anal pressure always remained higher than rectal pressure during rectal distension in normal subjects (P less than 0.05) but not in patients. The threshold rectal volume required to cause a desire to defaecate and the maximum tolerable volume were significantly lower (P less than 0.05) in each of the patient groups, compared with normal subjects. The similarity in the results from patients with rectal prolapse, anterior mucosal prolapse and solitary rectal ulcer support the hypothesis that they share a common pathophysiology. In each of the groups, the rectum is hypersensitive and hyper-reactive, and weakness of the anal sphincter creates the conditions for prolapse of the rectum to occur into or through the anal canal.

Adult↗
PubMed1988

The surgical treatment of intestinal obstruction due to left sided carcinoma of the colon.

Forty two consecutive patients who underwent surgery for an obstructing carcinoma of the left colon over a 5 year period were studied retrospectively. Twelve patients underwent an initial defunctioning procedure with no hospital deaths but with four deaths after a mean follow-up of 25 months. Of the 30 patients who had a primary tumour resection, 7 died during the first hospital admission and a further 4 during a mean follow-up period of 23.7 months. The hospital mortality following primary resection was related to the site and timing of the anastomosis. During the first hospital admission 3 of 5 patients died after colocolic anastomosis, 3 of 10 died following ileocolic anastomosis, but only 1 of 15 died in those who did not have a primary anastomosis performed. The mean hospital stay of patients undergoing a delayed resection was 41 (s.e. (mean) 2.8) days compared to 24 (s.e. (mean) 2.8) days in those undergoing a primary resection. Primary tumour resection with a delayed anastomosis is recommended on the basis of these findings.

Adult↗
PubMed1978

Isolated complete transection of the common bile duct by blunt abdominal trauma.

Isolated complete transection of the common bile duct due to blunt trauma is rare. Its occurrence and successful treatment in an 8-year-old boy are described. Inital minor peritonism resolved quickly, followed by a deceptive asymptomatic period and insidious development of jaundice, anorexia, vomiting, pain, acholic stools and progressive abdominal distension due to sterile biliary ascites. A preliminary cholecystostomy was followed by construction of a Roux-en-Y cholecystojejunostomy.

Abdominal Injuries↗
PubMed1976

Riedel's thyroiditis.

Riedel's thyroiditis is a rare chronic inflammatory disease of unknown aetiology and may be one manifestation of multifocal fibrosis. Four patients were seen over a period of 12 years and unusual presentations in 3 of them caused difficulty in diagnosis. The aetiology and methods of treatment are discussed.

Asphyxia↗
PubMedDate not supplied

Fine needle aspiration of palpable breast lesions. Results obtained with cytocentrifuge preparation of aspirates.

The use of cytocentrifugation in the preparation of fine needle aspiration (FNA) specimens from the breast was evaluated. A total of 174 fine needle aspirates of breast masses were flushed into cytospin Collection Fluid, from which Papanicolaou-stained Cytospin preparations were made in the laboratory. Comparison of these preparations to conventional smears of aspirates showed no significant differences in the number or morphology of the cells. In 148 cases, the FNA cytologic study was followed up by excisional biopsy, Tru-Cut biopsy and/or a combination of mammography and clinical follow-up of two to nine months. Of 36 verified carcinomas, 31 (86%) were correctly diagnosed, with a zero false-positive rate. Among the 74 cytologically benign aspirates, 2 carcinomas were found on open biopsy, giving a false-negative rate of 3%. Lipomas were not diagnosable with this technique. This technique should be considered in institutions with a high turnover of junior staff members, which frequently results in a higher number of poorly smeared specimens or in poorly fixed/air-dried specimens that give suboptimal results with the Papanicolaou stain. With this method, there is less risk of creation of potentially hazardous aerosols and further preparations for additional studies may be made if required.

Adenofibroma↗